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Water and the tar sands

The much-noted ‘Scraping Bottom’ article in the most recent issue of National Geographic highlights the following points about water and the tar sands.

“To extract each barrel of oil from a surface mine (in the Athabasca Valley, the industry) must heat several barrels of water to strip the bitumen from the sand and upgrade it, and afterward it discharges contaminated water into tailings ponds like the one near Mildred Lake. They now cover around 50 square miles.” (p.44)

“Mildred Lake…is now dwarfed by its neighbour, the Mildred Lake Settling Basin, a four-square-mile lake of toxic mine tailings. The sand dike that contains it is by volume one of the largest dams in the world.” (p.43)

“And every day in the Athabasca Valley, more than a million tons of sand emerges from (rock) crushers and is mixed with more than 200,000 pounds of water that must be heated, typically to 175 degrees F, to wash out the gluey bitumen.” (p.48)

MOST OF THE OIL REQUIRES WATER TO EXTRACT “In situ extraction, which is the only way to get at around 80 percent of those 173 billion barrels (of oil that are economically recoverable today), can use up to twice as much energy as mining because it requires so much steam. Most of the energy to heat the water or make steam comes from burning natural gas…” (p.48)

NAPTHENIC ACID AND POLYCYCLIC AROMATIC HYDROCARBONS “As the thick, brown slurry gushes from the discharge pipes, the sand quickly settles out, building the dike that retains the pond; the residual bitumen floats to the top. The fine clay and silt particles, though, take several years to settle, and when they do, they produce a yogurt-like goop – the technical term is ‘mature fine tailings’ – that is contaminated with toxic chemicals such as naphthenic acid and polycyclic aromatic hydrocarbons (PAH) and would take centuries to dry out on its own. Under the terms of their licenses, the mines are required to reclaim it somehow, but they have been missing their deadlines and still have not fully reclaimed a single pond.” (p.54)

45,000 GALLONS OF TOXIC WATER LEAK EVERY DAY “In the oldest and most notorious (tailings pond), Suncor’s Pond 1, the sludge is perched high above the river held back by a dike of compacted sand that rises more than 300 feet from the valley floor and is studded with pine trees. The dike has leaked in the past, and in 2007 a modeling study done by hydrogeologists at the University of Waterloo estimated that 45,000 gallons a day of contaminated water could be reaching the river.” (p.54-55)

“The Alberta government asserts that the river is not being contaminated – that anything found in the river or its delta, at Lake Athabasca, comes from natural bitumen seeps…(But) an Environment Canada study did in fact show an effect on fish in the Steepbank River, which flows past a Suncor mine into the Athabasca. Fish near the mine…showed five times more activity of a liver enzyme that breaks down toxins – a widely used measure of exposure to pollutants – as did fish near a natural bitumen seep on the Steepbank.” (p.55)

CHOLANGIOCARCINOMA CANCER IN FORT CHIPEWYAN Fort Chipewyan is downstream of the mines and located on Lake Athabasca. “In 2006 John O’Connor, a family physician who flew in weekly to treat patients at the health clinic in Fort Chip, told a radio interviewer that he had recent years seen five case of cholangiocarcinoma – a cancer of the bile duct that normally strikes one in 100,000 people. Fort Chip has a population of around 1,000; statistically it was unlikely to have even one case.” (p.58)